Triazole azo and azoxy dyestuffs



United States Patent Ofilice 2,693,464 Patented Nov. 2, 1954 TRIAZOLEAZO AND AZOXY DYESTUFFS Walter Hanhart, Riehen, Switzerland, assiguor toCiba Limited, Basel, Switzerland, a Swiss firm No Drawing. ApplicationJuly 16, 1951, Serial No. 237,060

Claims priority, application Switzerland July 21, 1950 8 Claims. (Cl.260-143) According to the present invention new, valuable azo dyestuffsare obtained when a diazo compound of an amine of the general formula inwhich R indicates an aromatic radical which contains at the most twocondensed rings and is condensed with the triazole ring at the positionsindicated by the valence bonds and Z indicates an azo or azoxy group, iscoupled with a pyrazolone and, if desired, the dyestuft thus obtainedtreated with an agent providing metal. Thus R may be a naphthaleneradical free from further auxochromic groups. As starting materials such3-methyl-5- pyrazolones may be used as are substituted in l-position byan aromatic radical of the benzene or naphthalene series which is freefrom sulfonic acid groups, preferably by a diphenyl radical. Thefollowing remarks may be made with regard to the starting materials ofthe present process:

The compounds of the formula set forth above may be prepared in variousways.

Thus, for example, diazotized 4-nitro-4'amino-stilbene-2:2-disulfonicacid may be coupled with an aromatic amine which couples in adjacentposition to the amino group, the o-aminazo dyestuif then oxidized to thetriazole and the latter condensed on the nitro group with2:S-diamino-benzene-l-carboxylic acid. As azo components there areconcerned in this case, for example, amines of the naphthalene serieswhich couple in o-position to the amino group and preferably such ascontain no further auxochromic group, as for example: 2-aminonaphthalene, l-aminonaphthalene-4- or -5-sulfonic acid,2-aminonaphthalene-6- or -7-sulfonic acid,l-aminonaphthalene-4:8-disulfonic acid, Z-aminonaphthalene- 3:6-disulfonic acid.

Instead of carrying out the condensation mentioned above, the nitrotriazole compound can also be reduced to the amino triazole compound andthis latter diazotized and coupled with 2-aminobenzene-l-carboxylicacid.

A further method for the production of the starting materials set forthabove consists in that diazotized 4-nitro-4'aminostilbene-2:2'-disulfonic acid is coupled withZ-aminobenzene-l-carboxylic acid, the amino group in the aminoazodyestuff thus obtained is acylated (for example acetylated), the nitrogroup in 4-position of the stilbene radical reduced to the amino groupand thereupon the reduction product diazotized and coupled with an amineof the naphthalene series which couples in adjacent position to theamino group, the oxidation of the o-aminazo grouping to the triazolethen carried out and finally the acylamino group hydrolyzed.

The reactions necessary for the preparation of these starting materialscan all be carried out in the conventional manner. The couplings withthe aromatic amines which couple in adjacent position to the aminogroup, are suitably effected in a weak acid medium. The oxidations tothe triazoles can be brought about. for example, by means of alkalihypochlorite or also by heating in the presence of copper salts. Thecondensation of the nitro monoazo dyestuif with the2:S-diaminobenzene-l-car- COOH boxylic acid is conducted, for example,by heating these substances in dilute alkali hydroxide solution.

The reduction of the nitro compounds to the amines must obviously becarried out in such a manner that the azo group is not attacked, forexample by means of alkali or ammonium sulfides at about -70" C. TheZ-aminobenzene-l-carboxylic acid is suitably coupled in a weakly acidmedium, for example acid with acetic acid and buffered with alkaliacetate, and in the form of the wmethane sulfonic acid. When thecoupling is complete, the .w-methane sulfonic acid group is split off,for example by heating in dilute alkali hydroxide solution.

The pyrazolones which likewise serve as starting materials in thepresent process may preferably be l-aryl- 3-methyl-5-pyrazolones,especially such as contain in 1- position an aromatic radical of thebenzene series. Valuable results are obtained, for example, withpyrazolones of the formula in which R indicates a radical containing twobenzene rings, one benzene ring being attached directly to the nitrogenatom of the pyrazolone ring, and being itself attached in one of thepositions meta or para to its own point of attachment, directly or by'means of a bridge member, for example a -CONH-OC or -O bridge, to thesecond benzene ring. As examples of suitable pyrazolones there my bementioned:

1 phenyl-3-methyl-5-pyrazolone, 1-[l': l"-diphenyl- (4')l-3-methyl-5-pyrazolone of the formula l- -QQ 1 [4"benzolylamino-l':l"-diphenyl-(4)J-3-methyl- S-pyrazolone, l-[4"-aminoor4"-acetylamino-l':1"-diphenyl-(4') J-B-methyl-S-pyrazolone, l-[naphthyl- (2') 3 methyl 5 pyrazolone, (3' or 4 benzoylamino)- phenyl3-methyl-5-pyrazolone, l-phenyl-( l)-3-methyl- 5-pyrazolone-3-carboxylicacid phenylamide.

If desired pyrazolones also containing sulfonicvacid groups can be usedsuch as l-(3'-or 4'sulfo)-phenyl- 3-methyl-5-pyrazolone.

As regards the manufacture of the new dyestufi's themselves thefollowing remarks may be made with respect to the first processmentioned above:

The diazotization of the amines of the formula set for above, takesplace with advantage by the socalled indirect method, that is to say bycombining a solution of an alkali salt of the compound to be diazotized,which solution contains a small excess of alkali, with an excess ofdilute hydrochloric acid.

According to a further feature of the invention the dyestuffs can bemanufactured by a modified process in which an amino azo dyestuff of theconstitution COOH in which R indicates an aromatic radical containing atthe most two condensed rings, which radical contains an NI-Iz-group inadjacent position to the azo group, Z an azo or azoxy group and Py theradical of a 5-pyrazolone attached in 4-position to the azo group, isoxidized to the triazole. This oxidation is advantageously carried outwith an alkali hypochlorite or a copper salt. If the oxidation takesplace with a copper salt then the result is the formation of theo-carboxy-o-hydroxy copper complex of the dyestuff. If it is desired toproduce the dyestuif free from copper, the copper can be removed in theconventional manner, for example by and finally coupling. with an amineof the. naphthalene series which couples in adjacent position to theamino rou g What has been stated with regard to theprocess ofmanufacture initial-1y describes also applies mutatis mutandis incarrying out this modified process and the preparation of the. startingmaterials required therefor. The dyestuffs obtainable according toeither of the methods of the present process, are new and correspond tothe general formula OOOH N 3H I HOsS in which R indicates an aromaticradical which contains at the most two condensed rings and is condensedwith the tria'zole ring at the positions indicated by the valence bonds,Z anazo or azoxy group and Py the radical of a 5-pyrazolone attached. in4-positionto the azo group. Thus R may be a naphthalene radical freefrom further auxochromic groups. Py may be the radical of. a.3methyl-5-pyrazolone which is substituted in 1- position by an aromaticradical of the benzene series which is free from sulfonic acid groups,preferably a diphenyl radical.

is. the customary way of indicating the triazole radical. It is. onlyintended to show that in this radical three nitrogen atoms are presenttogether with two carbon atoms which are themselves attached together(in this case belonging to an aromatic 6-membered ring), it is notintended to express anything definite with regard to the nature of thebonds which connect the nitrogen atoms among themselves or' to thecarbon atoms.

The dyestuffs corresponding to the above formula are suitable for thedyeing of a wide. variety of materials, for example animal fibers suchas wool, silk and leather, but especially for the dyeing and printing ofcellulosic materials such as cotton, linen, artificial silk and staplefiber from regenerated cellulose. The dyestuifs may be converted insubstance, in the dyebath and on the fiber into complex metal compounds,for example copper, chromium, iron, nickel or cobalt compounds. Theconversion. into such complex metal compounds takes place byconventional methods. in an acid; neutral or alkaline medium, with orwithout pressure and with or without additions such as salts ofinorganic or organic acids, such as tartaric acid, or of acid-bindingagents or agents promoting the complex formation, such as pyridine. Themanufacture of the metal compounds, especially the copper compounds, insubstance, is of especial value when the metal-containing dyestuffspossess a suificient solubility (this is as a rule the case withdyestuffs containing four sulfonic acid groups). When the dyestuffsobtainable according to the present process contain only few'solubilizing groups (for example only two or three sulfonic acid groupsand the carboxyl group in o-position to the azo group) they can withadvantage be treated on the fiber or partly on the fiber and partly inthe dyebath, with agents providing metal according to conventionalprocesses. With advantage, for example, the process of U. S. Patent No.2,148,659 can be used, according to which, in the same bath, firstdyeing is carried out and then the treatment with agents providingmetal. As agents. providing metal there are preterably applied in thiscase such as are stable towards alkaline solutions, such as complexcopper tartrates.

In some cases especially valuable dyeings can be obtained by working bytheprocess according to which the dyeings or printings produced with themetal-free dyestuffs, are after-treated with such aqueous solutions ascontain the basic formaldehyde-condensation products of compounds whichcontain in the molecule at least once the atom grouping.

or, as for example in the case of cyanamide, are easily converted intosuch compounds, and water soluble, especially complex, copper compounds.Such processes are described for example in British Patent No. 619,969.

The following examples illustrate the invention, the parts being byweight unless otherwisestated and the percentages also being by weightand the relation between parts by weight and parts by volume being thesame as that between the kilogram and the litre:

Example 1 63.2 parts of the compound of the formula OaH (obtainable bycoupling diazolized 4-nitro-4'-amino-stilbene-2:2-disulfonic acid with1-aminonaphthalene-4- sulfonic acid and oxidizing the obtained azodyestufi) in the form of the sodium salt, are dissolved in 500 parts ofhot water. A hot solution of 18 parts of2:5'-diaminobenzene-l-carboxylic acid in 200 parts of water and 16 partsof sodium hydroxide solution of 30 per cent. strength is introduced andthen parts of sodium hydroxide solution of 30 per cent. strength furtheradded and the whole boiled for 4 hours and the dyestuff precipitatedwith 80 parts of sodium chloride and, after cooling filtered off. It iswashed on the filter with 10 per cent. sodium chloride solution. Ifdesired this dyestuff can be purified by dissolving it in dilute sodiumhydroxide solution, precipitating again by addition of sodium chlorideand filtering. 41 parts of the sodium salt, thus obtained, of themonoazo dyestufi, are dissolved in 500 parts of hot water, treated with3.5 parts of sodium nitrite in the form of a 20 per cent. solution andthe whole poured out with good stirring into ice and 27.5 parts of 30per cent. hydrochloric acid. Stirring is carried out for several hourswith cooling followed by treatment with a solution of 9.1 parts of1-phenyl-3-methyl-5- pyrazolone in parts of water, 6.9 parts of 30 percent. sodium hydroxide solution and 25 parts of sodium carbonate. Whenthe coupling is complete the dyestuff is filtered off and dried; itforms a brown-red powder which dissolves in concentrated sulfuric acidwith a violet and in water with an orange coloration. Cotton is dyed bythe singleor two-bath after-copperiug process, in outstandinglylight-fast orange shades which also possess good fastness properties towet processing.

A product which is very similar in its properties to the dyestufidescribed in the above paragraph, can also be obtained by coupling ofthe diazotized aminostilbene triazole of the formula SOaH $0311 SOaHwith the w-methane sulfonic acid of the Z-amino-l-benzoic acid withsubsequent hydrolysis.

' A dyestutf which also has very similar properties to that described inthe first paragraph of this example, can also be produced in thefollowing manner:

4-n1tro-4-aminostilbene-2:2disulfonic acid is diazotized, coupled withthe w-methane sulfonic acid of 2- aminobenzene-l-carboxylic acid,thereupon the cu-methane sulfonic acid radical split off by acid oralkaline treatment and the monoazo dyestuft diazotized and coupled withthe pyrazolone. The nitro group of the dyestuif is reduced to the aminogroup by heating with sodium sulfide and this group is then diazotizedand the triazo dyestuff formed by coupling with l-aminonaphthalene-4-sulfonic acid. The triazole compound is obtained by oxidation with acopper solution alkaline with ammonia. In order to obtain the dyestufffree from copper, it is demetallized according to one of theconventional methods, for example by heating with hydrochloric acid ofabout 4 per cent. strength.

Another possibility of arriving at the dyestufr' of the precedingparagraph consists in that the intermediate product named in thatparagraph SOaH SIOaH C O OH is aoetylated on the amino group, thereuponthe nitro group of the dyestuff reduced to the amino group and thelatter diazotized and coupled with l-aminonaphthalene-4-sulfonic acid.By oxidation with a copper solution there is obtained the triazolecompound, the acylamino group of which is hydrolyzed and the amino groupthus liberated thereupon diazotized. By coupling with the pyrazolone thesame final dyestuff is obtained.

Dyestuffs with even better wet fastness properties are obtained when thel-phenyl-3-methyl-5-pyrazolone is replaced by l-[l l-diphenyl-(4)l-3-methyl-5-pyrazolone, 1-[4-acetylamino-l':l-diphenyl (4')] 3methyl-5- pyrazolone, 1-(4'-benzoylamino)-phenyl 3 methyl-5- pyrazoloneor l-naphthyl(2)-3-methyl-5-pyrazolone.

Example 2 80 parts of the trisodium salt of the dyestufi of the formulaSOaH SOsH OH wherein Z represents an azo or azoxy group, obtainable bycondensation of 4:4'-dinitrost1lbene-2:2-d1- sulfonic acid with2:S-diaminobenzene-l-carboxylic acid, diazotization of the condensationproduct obtained and coupling of the diazo compound with l-phenyl-3-methyl-S-pyrazolone) are heated in 1500 parts of water to 65 0, treatedwith a solution of 41 parts of crystalline sodium sulfide in 200 partsof water and the whole stirred for 3 hours at 60-65 C.. 250 parts ofsodium chloride are introduced and, after cooling, the product isfiltered and Washed with sodium chloride solution of 10- 15 per cent.strength. The aminodisazo dyestulf obtained is dissolved with heating in1000 parts of water and after the addition of 7 parts of sodium nitritein the form of a 20 per cent. solution, poured out with good stirringinto ice and 55 parts of 30 per cent. hydrochloric acid. The whole isstirred for a few hours with cooling, any excess of nitrite destroyedwith sulfamic acid, coupling is effected with a neutral solution of 32parts of l-aminonaphthalene-4:8-disultonic acid and the mineral acid sneutralized with sodium acetate. When the coupling 1s complete the wholeis rendered alkaline with sodium hydroxide solution and the dyestuflprecipitated w1th 100 parts of sodium chloride. The trisazo-dyestulfobtained is dissolved with heating in 2000 parts of water and treated at95 C. with an alkaline copper solution consisting of 100 parts ofcrystalline copper sulfate, 500 parts of water and 270 parts of a 24 percent. ammonia solution. Stirring is carried on for several hours atabout 95 C., followed by cooling, rendering slightly acid to Congo withhydrochloric acid and filtering otf of the dyestuft. The latter, in thedry state, is a brown-red powder which dissolves in concentratedsulfuric acid with a violet, in dilute sodium carbonate solution with anorange-red coloration and which dyes cotton in orange shades which areextraordinarily fast to light.

A similar dyestulf which is likewise very fast to light, is obtainedwhen the 1-aminonaphthalene-4:8-disulfonic acig is replaced by2-aminonaphthalene-3z6-disulfonic aci Example 3 80 parts of thetrisodium salt of the dyestufif of the formula set forth in Example 2are reduced and diazo tized according to the directions of Example 2.Any excess of nitrite is destroyed with sulfamic acid and the diazocompound is combined, in the presence of sodium acetate, with asuspension of 14.5 parts of 2-aminonaphthalene, the dyestutf beingfiltered off when the coupling is complete. This dyestuff is heated in3000 parts of water to C. with the addition of 20 parts of a 24 percent. ammonia solution, treated with a solution of parts of crystallinecopper sulfate in 500 parts of water and 270 parts of a 24 per cent.ammonia solution and the Whole stirred for several hours at about 95 C.After the mixture has been acidified with hydrochloric acid, thedyestutf is filtered off and, for removal of the copper, boiled forabout 6 hours in 1000 parts of 4 per cent. hydrochloric acid. Thefiltered and dried dyestutf forms a brown-red powder which dissolves inconcentrated sulfuric acid with a violet and in dilute sodium carbonatesolution with a yellow-red coloration. By the single-or two-bathafter-coppering process there are obtained on cotton orange colourshades of very good fastness to light and good wet fastness properties.

Instead of being carried out, as above described, with copperoxide-ammonia, the oxidation to the triazole can also be effected withsodium hyprochlorite. For this purpose the trisazo dyestuff is broughtinto a finely dispersed form as follows: The dyestuif paste is stirredinto 6000 parts of water, rendered weakly alkaline with sodium hydroxidesolution, heated to 100 C. and cooled to about 35 C. by addition of ice.After the introduction of 10 parts of sodium chloride for each 100 partsby volume of the reaction mixture, cooling to 25 C. is carried out andat this temperature 225 parts of sodium hypochlorite solution containing13-l4 per cent. of active chlorine then introduced. After a short timethe brown colour OH I I I Q of the suspension has changed to orange andthe dyestufi now dissolves is concentrated sulfuric acid with a violetcoloration (previously the coloration was blue). As soon as no furtherchange takes place, any excess of oxidizing agent is destroyed, forexample with sodium thiosulfate, and the dyestuff is filtered 011?. Itis practically identical with that described above.

Dyestuffs which when dyed according to the singleor two-bathafter-coppering process, give dyeings of still better fastness towashing, are obtained when instead of the starting dyestufi obtainablefrom l-phenyl-3- methyl-S-pyrazolone, the corresponding dyestuffs areused produced from 1-[4"-acetylamino-l:l"-diphenyl-(4)J-3-methyl-5-pyrazolone or 1-(3'- or 4-benzoy1 amino) -phenyl-3-methyl-5-pyrazolone.

Example 4 100 parts of cotton are entered at 50 C. into a dyebath whichcontains, in 4000 parts of. water, 1 part of the dyestuff obtainableaccording to the first paragraph of Example 1 and 2 parts of anhydroussodium carbonate, the temperature is raised in the course of 20 minutesto 9095 C., 40 parts of crystalline sodium sulfate are added and dyeingis carried on for 30 minutes at 90- 100 C. Thereupon the whole isallowed to cool to about 70 C., 1 part of complex sodium copper tartrateof approximately neutral reaction is added, coppering follows for /2hour at about 80 C. and the dyeing is then rinsed with cold water. Ifdesired the dyeing can be soaped by after-treatment with a solutioncontaining 5 parts of soap and 2: parts of anhydrous sodium carbonate in1000 parts by volume of water. An orange dyeing is obtained of goodfastness to light and washing.

7 8 What is claimed is: azoxy group and R1 represents an aromaticradical con- I. An azo dyestufi of the formula taining at the most two'six-membered rings, R1 being OH N 00011 .1

C-NRi i/ g C=N N 05H HOa e in which R represents a naphthalene radicalwhich is free from sulfonic acid groups. condensed with the triazolering at the positions indicated 3. An azo dyestufi of the formula OH00011 ([1 N\ N-- v N I I C=N SOaH HOaS A0311 by the valence bonds andcontains as the only substituent wherein Z stands for a member selectedfrom the group at least one and at the most two sulfonic acid groups,conslstmg of an azo group and an azoxy group. Z represents a memberselected from the group COIlSlSi- 4. An azo dyestulf of the formula onOOOH l N g E C=N 03H HO: A)

OaH ing of an azo and an azoxy group, and R1 represents wherein Z standsfor a member selected from the group an aromatic radical containing atthe most two six-memconsisting of an azo group .and an azoxy group.bered rings, R1 being free from sulfonic acid groups. 5. An azo dyestuflof the formula NH-OC-O N g C=N 03H 2. Complex copper compound of an azodyestufl of wherein Z stands for a member selected from the group theformula consisting of an azo group and an azoxy group.

0H N 00011 J -N i a R i N- -orr=cH--z- N=N-0 C='N N/ OaH 1103i! H:

in which R represents a naphthalene radical which is 6. azo dyestufl? ofthe formula OH 'O O 0 H I N\ I /CN I; l N c:

doll! Hots N OsH condensed with the triazole ring at the positionsindiwherein Zstands .for a member selected from the group cated by thevalence bonds and contains as the only consisting of an azo group and anazoxy group. substituents two sulfonic acid groups, Zrepresents a mem-7. Complex copper compound of an azo dyestufi of her selected from thegroup consisting of an azo and an the formula OH N Q no 8 wherein Zstands for a member selected from the group consisting of an azo groupand an azoxy group.

8. A dyestuif selected from the group consisting of a dyestufi of theformula References Cited in the file of this patent Number 20 2,3 14,0232,394,998 240535 3 2,467,262

UNITED STATES PATENTS Name Date Straub et al. Mar. 16, 1943 Keller Feb.19, 1946 Hanhart Aug. 6, 1946 Knight Apr. 12, 1949

8. A DYESTUFF SELECTED FROM THE GROUP CONSISTING OF A DYESTUFF OF THEFORMULA